Walter Biles Posted January 17, 2015 Share #1 Posted January 17, 2015 (edited) This illustration comes from the steam tank that we used for preparing planks for bending at the Severn River Repair Center when I was in the Navy. The steam was regulated to about 30psi. There was a shelf of expanded metal all the way through the steamer to hold the planks up out of the condensate. The valve on the upper right of the picture was opened after loading the lumber into the opening hatch on the left end and it was dogged down fully. The steam was allowed to enter the tank with the bleed valve at the left bottom open for a few minutes, then it was closed for a bit. After about 5 minutes when the steam pressure was up to it's setting, the condensate valve would be cracked enough open to allow the condensate to dribble. This allowed the steam to keep entering the tank, It was watched to make sure it did not let the steam to blow out. Once it was stable, we would leave the wood in it for about an hour, and at that time, the steam was shut off. Then the condensate valve could be opened all the way to let the pressure off. Once the pressure was down, and the steam had stopped blowing out, the dogs would be cracked and backed off carefully. One of the sand crabs(civilian shipwrights) showed me a piece of oak that I had helped him put in that was about 1"x2"x8' and I asked him how much bend could it take. He showed me by tying a loose overhand knot in it with about a foot of the plank sticking out each side of the knot. He then straightened it out, and used it on the boat he was working on. The pressure of the steam drove the moisture into the wood in just a little while. When the steam was down, ie. not available, they tied some weight to the timber and attached a line to it and dropped it in the basin overnight. That was not as effective as the steam, and it would not bend to the same degree without damage. I thought that some of you might find this interesting. Edited January 18, 2015 by Walter Biles butch, Mark P, figuerres and 9 others 12 Quote Link to comment Share on other sites More sharing options...
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